Some species of Brachiaria, generally tetraploid apomictic varieties, have become important forage grasses in the tropics. Breeding of Brachiaria depends on compatibility with the available apomitic tretraploid cultivars. This paper describes a procedure for chromosome duplication of two Bracharia brizantha diploid sexual accessions, using colchicine treatment of basal segments of in-vitro-grown plants. Explants were cultured on a medium containing 1 mg/l naphthaleneacetic acid, 3 mg/l kinetin and 0.01% colchicine for 48 h and transferred to the same medium without colchicine until shoot regeneration occurred. Regenerated plants were screened by flow cytometry, and chromosome number duplication was confirmed by cytological analysis of root tips.

Lipid supplements (oilseeds vegetables) are included in ruminant diet to increase its energy density and improve fatty acid composition of milk and consequently of fresh cheese. Milk and cheeses were evaluated from crossbred Holstein × Zebu, fed diets enriched with 0%, 25%, 50%, and 75% inclusion levels of palm kernel cake in concentrated supplement, which were supplied daily (3.0 kg). Milk and fresh cheese (p = 0.001) fatty acids C12:0 exhibited quadratic negative values. Milk fatty acids C13:0, C20:0, C18:2t10c12, and C20:2n-6 presented positive quadratic values. The milk C18:2n-6 decreased linearly and in fresh cheese exhibited an increasing linear effect (p = 0.016). However, the fatty acids grouped in milk fat were not affected. The medium-chain fatty acids varied negatively and quadratically (p = 0.045). There was no effect on milk and fresh cheese chemical composition (p > 0.05). The milk fat was increased (p = 0.0065) quadratically (minimum point of 24.7%). Thus, the addition of palm kernel cake to cow diets negatively altered the fatty acid profile, it raises the percentage OPEN ACCESSMolecules 2015, 20 15435 of lauric (C12) and tridecanoic (C13) acids fat which is not beneficial to human health from a nutraceutical perspective, although it did not influence the atherogenicity index.

Avaliou-se o efeito da inclusão de diferentes níveis (0, 5, 10 e 15%) de bagaço de mandioca à dieta de 12 vacas mestiças leiteiras Holandês x Zebu (composição racial com variação de ¼ a ¾ de sangue H x Z) com 478,5kg de peso corporal médio e com 100 a 150 dias de lactação, distribuídas em três Quadrados Latinos 4 x 4. Foi avaliado o consumo de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), carboidratos totais (CHT), carboidratos não-fibrosos (CNF) e nutrientes digestíveis totais (NDT). Forneceu-se silagem de capim-elefante como fonte de volumoso. As relações volumoso:concentrado utilizadas foram de 65,19:34,81; 61,59:38,41; 59,08:40,92 e 54,76:45,24. Formularam-se as dietas isoprotéicas e isoenergéticas. Houve aumento linear do consumo de MS, MO, PB, CHT, CNF e NDT, efeito quadrático do consumo de EE e redução do consumo de FDA com o aumento do BM, enquanto o consumo de FDN não diferiu entre os tratamentos.O bagaço de mandioca pode ser utilizado até o nível de 15% de inclusão na dieta total de vacas mestiças leiteiras sem trazer transtornos fisiológicos ou nutricionais aos animais.

-The objective of this study was to evaluate the nutritional and productive characteristics of primiparous lactating cows grazing on tropical pasture, using different levels of crude glycerin in the supplement. The experiment was conducted at Rancho Santana farm, located in Jequié city, Bahia, Brazil, in the period from December 21, 2010 to March 16, 2011. Ten ¾ Holstein × ¼ Dairy Gyr lactating primiparous cows, with 109±24 days of lactation and a mean age of 30±6 months and mean body weight of 426.2±68.29 kg were distributed into five treatments, using two simultaneous 5 × 5 latin squares. Treatments consisted of inclusion levels (0, 94, 191, 289, 389 g/kg dry matter basis) of crude glycerin in the supplement. Intake, digestibility, milk production and composition were measured. Results were statistically analyzed by analysis of variance and regression at 0.05 probability. For all consumption variables no significant differences were found between the levels of crude glycerin. Except for the digestibility of ether extract, all digestibility values were similar between treatments. The fat content and yield showed quadratic effect between treatments. No significant differences were observed for protein, lactose, total solids, nonfat dry extract, fat:protein ratio, milk urea nitrogen and somatic cell count between treatments. For primiparous lactating cows grazing on tropical pasture, up to 389 g of crude glycerin/kg of dietary supplement can be included without nutritional and productive interference.